The present invention relates to a starch-free cultured yogurt having a low fat content and to a process for the manufacture thereof. More specifically, the present invention relates to an improved shelf-stable when refrigerated, low-fat cultured yogurt product having greater natural sweetness and more non-fat milk solids than ordinary yogurts, with improved body, flavor, texture, smoothness, taste and appearance.
Yogurt is the product obtained when a milk solution is fermented with lactic acid producing microorganisms to the level of acidity which coagulates the solution and inhibits the further growth of the bacteria. To produce natural yogurt, a conventional yogurt culture such as Lactobacillus bulgaricus, Lactobacillus acidophilus, and Streptoccocus thermophilus is implanted in normal or modified milk and allowed to incubate until the bacteria establish the proper pH in the milk. After the proper pH is established and the yogurt jells, the product is chilled and kept in a protected container to inhibit the growth of undesirable microflora, that would produce spoilage. Yogurt must contain at least 0.6% acidity expressed in terms of lactic acid.
The benefits to be gained from eating yogurt culture are generally recognized, as for example, in its nutritional value and in the control of intestinal fermentation through the contribution of bacteria to the lower intestines which predominate over putrifactive microflora.
For the benefits of yogurt cultures to be realized, an effective amount of yogurt culture must be included in the diet daily. Generally, L. bulgaricus, the necessary organism for the production of yogurt but one which is unable to proliferate (or even survive) in the human bowel, is combined with another compatible bacteria such as L. acidophilus or Str. thermophilus to obtain the therapeutic effects. However, not all brands of yogurt currently on the market contain an effective amount of yogurt culture, the premixed or Swiss type being of particular note since the cultures in these are often deactivated by the processing.
A high quality yogurt contains, therefore, an effective amount of active culture along with beneficial nutrients such as protein, calcium, vitamins, is starch free and is low in butterfat. The texture of yogurt is also an important factor in determining its acceptance, for yogurt should be free of lumps or curds and exhibit a custard-like consistency until the set is broken and the whey is released.
Recently, the use of yogurt as a frozen dessert has become very popular because of its nutritional benefits over ice cream, for example. When yogurt is used frozen, it has, in many instances, had a sweetening agent such as sugar or saccharin added to it, to make it more similar to ice cream and other desserts. In these uses the proportion of high liquid and low solids content of ordinary yogurt has usually been retained with the result that the product tends to form into crystals when stored at or below freezing temperature for an extended period of time. Also, when yogurt is used as a soft frozen dessert, starches, non-fermented milk products and other additives or thickeners are often included in the product which may interfere with the effect desired from the fermented product, or may increase the calories per serving without necessarily increasing the nutritive value.